December 26, 2013 10:48 am Bieber Tweets Leave Fans Confused 19-year-old pop star Justin Bieber took to twitter to announce his retirement. But additional tweets left fans wondering exactly what that means. US & World Videos 1:40 Charlie Puth reacts to Taylor Swift's ‘The Tortured Poets Department' name-drop 2:52 Severe weather kills at least 5 as tornadoes rip through Midwest and South 0:48 World Central Kitchen to resume operations in Gaza 8:39 Gina Rodriguez gushes 0ver motherhood with son Charlie 2:22 Scarlett Johansson and Colin Jost have date night at White House Correspondents' dinner